Methods for measuring optical properties and systems for measuring optical properties

Abstract

Method for measuring optical properties of an object (S), wherein the method for measuring optical properties comprises: a step of capturing one or more recorded image(s) that includes the object (S), using an image capture device (31, 51) that is located at a predetermined distance from the object (S) and is moved relative to the object (S) along a trajectory (L) while maintaining the predetermined distance; and a step of generating, on the basis of the one or more captured images, a virtual image encompassing the object (S) and virtually captured by one or more analysis point(s) (Ap), each of which is located at a position different from a position on a plane encompassing the trajectory (L) of the image-capturing device (31, 51).

Description

BACKGROUND OF THE INVENTIONField of the invention

[0001] The present invention relates to a method for measuring optical properties and a system for measuring optical properties for measuring optical properties of an object. Description of the state of the art

[0002] A technology for measuring the optical properties of an object, such as a light source, has been developed. For example, JP 2016-151437 A (Patent Document 1) discloses a device that measures the illuminance at a distance from a light source.

[0003] Specifically, the light distribution characteristic measuring device disclosed in Patent Document 1 is a light distribution characteristic measuring device for measuring light distribution characteristics of a light source, and includes: an image pickup unit located at a predetermined distance from the light source; a movable mechanism that continuously changes the position of the image pickup unit relative to the light source; and a processing unit that calculates light distribution characteristics of the light source based on a plurality of pieces of image data captured by the image pickup unit and relative positions of the image pickup unit relative to the light source at times when the plurality of pieces of image data are respectively captured.The processing unit acquires a plurality of pieces of image data captured under first image acquisition conditions and a plurality of pieces of image data captured under second image acquisition conditions different from the first image acquisition conditions. The processing unit further determines corrected image information corresponding to the relative position of interest based on first image information corresponding to a relative position of interest included in the plurality of pieces of image data captured under the first image acquisition conditions and second image information corresponding to a relative position of interest included in the plurality of pieces of image data captured under the second image acquisition conditions. SUMMARY OF THE INVENTION

[0004] There is a need for a technology that enables more preferable measurement results to be acquired with a configuration for measuring optical properties of an object, such as the light distribution characteristic measuring device disclosed in Patent Document 1, using captured images of the objects.

[0005] The present invention has been made to solve the above-described problem, and an object of the present invention is to provide an optical property measuring method and an optical property measuring system that can acquire more preferable measurement results with a structure for measuring optical properties of an object using captured images of the object.

[0006] The object of the present invention is achieved by the subject matter of the independent patent claims. Preferred embodiments are defined in the dependent patent claims.

[0007] (1) An optical property measurement method according to one aspect of the present invention is an optical property measurement method for measuring optical properties of an object, the optical property measurement method comprising: a step of acquiring one or more captured images including the object using an image pickup device that is located at a predetermined distance from the object and is translated relative to the object on a trajectory while maintaining the predetermined distance;and a step of generating, on the basis of the one or more captured images thus acquired, a virtual image comprising the object and virtually acquired from one or more analysis points each located at a position different from a position on a plane comprising the trajectory of the image capturing device;

[0008] The inventors of the present invention considered measuring light reaching the analysis points in terms of which captured images can be acquired when images of the subject are captured from the analysis points, rather than simply measuring the intensity of light from the subject at the analysis points. As described above, with the method of generating virtual images from the analysis points using an image captured from a point located at a position different from that of the analysis points, a larger amount of information can be reliably acquired at various analysis points compared to a method of simply measuring the intensity of light from the subject at one analysis point.Therefore, with a setup for measuring optical properties of the object using captured images of the object, more preferable measurement results can be acquired.

[0009] (2) Preferably, in the step of generating the virtual image, a plurality of virtual images virtually acquired from a plurality of analysis points are respectively generated, and the optical characteristic measuring method further comprises a step of calculating the sum of pixel values ​​of each of the plurality of virtual images thus generated.

[0010] Using such a method, the light intensity can be calculated for each analysis point. Therefore, the distribution of light intensities at any level can be captured with high accuracy.

[0011] (3) Preferably, in the step of generating the virtual image, one captured image is selected from a plurality of images captured from the trajectory based on a position on a virtual plane corresponding to the virtual image, the position of each of the one or more analysis points, and the plane, and the virtual image is generated based on the thus selected captured image.

[0012] With such a method, a suitable captured image can be selected for each position on the virtual plane according to the position on the virtual plane, the position of the analysis point, and the trajectory. Therefore, a virtual image with high accuracy can be generated.

[0013] (4) More preferably, in the step of generating the virtual image, a plurality of captured images are selected from a plurality of images captured from the trajectory, and the virtual image is generated on the basis of an image generated from the plurality of thus selected captured images.

[0014] With such a method, in a case where there is no captured image corresponding to a position on the virtual plane and the position of the analysis point captured from the trajectory, a plurality of appropriate images can be selected, and a virtual image can be generated with high accuracy.

[0015] (5) Preferably, in the step of acquiring the one or more captured images, a plurality of image pickup devices each capturing images at different wavelengths are used, and in the step of generating the virtual image, the virtual image is generated for each of the plurality of image pickup devices.

[0016] With such a method, for example, a plurality of captured images with a plurality of wavelengths captured simultaneously can be acquired. Furthermore, it is also possible to capture a captured image with different wavelengths in parallel, shortening the image acquisition period. Therefore, even if the intensity of the light from the object changes over time, it is possible to capture preferred captured images without being significantly influenced by such changes.

[0017] (6) More preferably, in the step of capturing the one or more captured images, the plurality of image capturing devices are used which are arranged along the circumference of the same circle centered on the object.

[0018] By arranging a plurality of image pickup devices such that the distance between each image pickup device and the object is the same, the computation processing can be simplified when, for example, an analysis is performed using a plurality of virtual images generated for the plurality of image pickup devices.

[0019] (7) More preferably, in the step of acquiring the one or more captured images, position information indicating the position of each pixel of the one or more images captured by the plurality of image capturing devices is corrected.

[0020] With such a method, even if the position of the object is different in each of the images captured by the plurality of image pickup devices, correction can be performed so that the position of the object is identical in each captured image, and then a virtual image can be generated for each wavelength. Therefore, it is possible to acquire even more preferable measurement results.

[0021] (8) More preferably, in the step of acquiring the one or more captured images, the plurality of image pickup devices each including light attenuation filters provided at positions in an image pickup direction are used.

[0022] With such a method, even if the light transmission rates of the plurality of optical filters respectively provided in the plurality of image pickup devices are different from each other, each image pickup device can capture an image with an appropriate light intensity.

[0023] (9) An optical property measuring system according to one aspect of the present invention is an optical property measuring system that measures optical properties of an object, the optical property measuring system comprising: an information processing device; an image pickup device located at a predetermined distance from the object; and a movable mechanism that can change the position of the image pickup device relative to the object on a trajectory while maintaining the predetermined distance.The information processing device is configured to generate a virtual image comprising the object and virtually captured by one or more analysis points located at a position different from a position on a plane comprising the trajectory of the image capturing device, based on an image captured by the image capturing device and comprising the object.

[0024] The inventors of the present invention considered measuring light reaching the analysis points in terms of which captured images can be acquired when images of the subject are captured from the analysis points, rather than simply measuring the intensity of light from the subject at the analysis points. As described above, with a structure that utilizes an image captured from a point located at a position different from the analysis points and can thereby generate a virtual image captured from the analysis point, it is possible to reliably acquire a larger amount of information at various analysis points compared to a structure that simply measures the intensity of light from the subject at one analysis point.Therefore, a setup for measuring optical properties of the object can acquire more preferable measurement results by using captured images of the object.

[0025] (10) Preferably, the information processing apparatus is configured to generate a plurality of virtual images each virtually captured from a plurality of analysis points and calculate the sum of pixel values ​​of each of the plurality of virtual images thus generated.

[0026] With such a setup, the light intensity can be calculated for each analysis point. Therefore, the distribution of light intensities at each level can be captured with high accuracy.

[0027] (11) Preferably, the information processing apparatus is configured to select a captured image from a plurality of images captured from the trajectory based on a position on a virtual plane corresponding to the virtual image, the position of each of the one or more analysis points and the plane, and to generate the virtual image based on the thus selected captured image.

[0028] With such a setup, a suitable captured image can be selected for each position on the virtual plane according to the position on the virtual plane, the position of the analysis point, and the trajectory. Therefore, a virtual image with high accuracy can be generated.

[0029] According to the present invention, a structure for measuring optical properties of the object can acquire more preferable measurement results by using captured images of the object.

[0030] The above and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when considered in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows an external structure of an optical characteristic measuring system according to an embodiment of the present invention. Fig. 2 shows a device structure of the optical characteristic measuring system according to the embodiment of the present invention. Fig. 3 shows a structure of a detector unit according to the embodiment of the present invention. Fig. 4 shows changes in the positions of image pickup devices according to the embodiment of the present invention. Fig. 5 shows trajectories of the image pickup devices according to the embodiment of the present invention. Fig. 6 shows processing performed by an information processing apparatus according to the embodiment of the present invention for calculating the light intensity. Fig. 7A shows an example of a virtual image generated by the information processing apparatus according to the embodiment of the present invention. Fig. 7B shows an example of a virtual image generated by the information processing apparatus according to the embodiment of the present invention. Fig. 8 shows a method of generating a virtual image used by the information processing apparatus according to the embodiment of the present invention. Fig. 9 shows a method of generating a virtual image used by the information processing apparatus according to the embodiment of the present invention. Fig. Fig. 10 shows a light analysis processing with respect to a point Px located in the Fig. 9 is shown. Fig. 11 shows compensation processing performed by the information processing apparatus according to the embodiment of the present invention. Fig. 12 shows an example of the distribution of light intensities that can be detected by analysis processing performed by the information processing apparatus according to the embodiment of the present invention. Fig. 13 shows an example of the distribution of light intensities that can be detected by analysis processing performed by the information processing apparatus according to the embodiment of the present invention. Fig. 14 is a flowchart showing a flow of operations performed by the information processing apparatus according to the embodiment of the present invention. Fig. 15 shows a structure of a first modification of the detector unit according to the embodiment of the present invention. Fig. 16 shows a structure of an optical filter unit included in the first modification of the detector unit. Fig. 17 shows a structure of a light attenuation filter unit incorporated in the first modification of the detector unit. DETAILED DESCRIPTION OF THE INVENTION

[0031] An embodiment of the present invention will be described below with reference to the drawings. Note that the same reference numerals are assigned to the same parts and equivalent parts in the drawings, and their descriptions will not be repeated. At least some parts of the following embodiment can be combined in any way. Structure and basic processesSystem for measuring optical properties

[0032] The Fig. 1 shows an external structure of an optical property measuring system according to an embodiment of the present invention. Fig. 2 shows a device structure of the optical characteristic measuring system according to the embodiment of the present invention.

[0033] As it is in the Fig. 1 and Fig. 2, an optical property measurement system 200 is a system that measures optical properties of an object S and includes an information processing device 10, a detector unit 11, a movable mechanism 12, a spectrometer 13, and a support platform 14 that supports the object S.

[0034] The object S is, for example, an object that emits light itself, such as a lamp or a display device, or an object that reflects light from a light source or allows it to pass through it. In particular, the object S is, for example, a display, such as a television set, an interior light, an exterior light, a motor vehicle light or a film. It should be noted that the shape of the object S is not limited to the shape shown in the Fig. 1 shown spherical shape.

[0035] The detector unit 11 comprises one or more image recording devices 31, in particular two-dimensional brightness measuring devices. As described in the Fig. As shown in Figure 2, the detector unit 11 includes three image pickup devices 31A, 31B, and 31C, each of which captures images at different wavelengths. In the following description, each of the image pickup devices 31A, 31B, and 31C may be simply referred to as an "image pickup device 31." The image pickup devices 31 are located at a predetermined distance from the object S.

[0036] The movable mechanism 12 changes the position of the detector unit 11 relative to the object S while maintaining the distance between the object S and the detector unit 11. As shown in the Fig. 1, the movable mechanism 12 comprises a first arm 21, a second arm 22, a first motor 23 capable of rotation in the direction indicated by arrow E1, and a second motor 24 capable of rotation in the direction indicated by arrow E2.

[0037] As a result of the first motor 23 causing rotation in the direction indicated by arrow E1, the first arm 21 coupled to the first motor 23, the second arm 22 coupled to the first arm 21 via the second motor 24, and the detector unit 11 attached to the second arm 22 rotate in the direction indicated by arrow E1. Furthermore, as a result of the second motor 24 causing rotation in the direction indicated by arrow E2, the second arm 22 coupled to the second motor 24 and the detector unit 11 rotate in the direction indicated by arrow E2.

[0038] In the Fig. 1, an axis extending in the vertical direction is defined as the Y-axis. Further, an axis extending along the horizontal plane and extending in a direction from the object S to the detector unit 11 when the detector unit 11 is at the position shown in the Fig. 1 is defined as the Z-axis. Furthermore, an axis extending along the horizontal plane and orthogonal to the Z-axis is defined as the X-axis.

[0039] The information processing device 10 is connected to the image pickup devices 31A, 31B, and 31C, the movable mechanism 12, and the spectrometer 13. The information processing device 10 transmits a measurement instruction to the spectrometer 13 via a LAN (local area network), for example, according to a user operation. After receiving a measurement instruction from the information processing device 10, the spectrometer 13 measures the spectrum of light from the object S according to the measurement instruction and transmits the measurement result to the information processing device 10 via the LAN.

[0040] Furthermore, the information processing device 10 transmits a drive instruction to the first motor 23 and the second motor 24 of the movable mechanism 12 via the LAN, for example, according to a user operation. After receiving the drive instruction from the information processing device 10, the first motor 23 and the second motor 24 rotate according to the drive instruction.

[0041] Further, the information processing device 10 transmits an image capture instruction to the image capture devices 31A, 31B, and 31C via GigE (Gigabit Ethernet (registered trademark)), for example, according to a user operation. Upon receiving the image capture instruction from the information processing device 10, the image capture devices 31A, 31B, and 31C each capture images, each centering on the subject S, in parallel, for example, at the same time, according to the image capture instruction, and transmit the captured images to the information processing device 10 via GigE.

[0042] Further, the information processing device 10 performs processing described below based on the measurement result from the spectrometer 13 and a plurality of captured images from the image pickup devices 31A, 31B, and 31C to analyze the optical properties of the object S. For example, the information processing device 10 calculates the light intensity at a given point Ap (hereinafter referred to as an "analysis point") located at a position different from a position on a plane including the trajectories of the image pickup devices 31.

[0043] In particular, the “position different from a position on a plane including the trajectories of the image pickup devices 31” may be at least one of a position inside or outside the plane. Detector unit

[0044] The Fig. 3 shows a structure of the detector unit according to the embodiment of the present invention.

[0045] As it is in the Fig. 3, the image pickup devices 31A, 31B and 31C in the detector unit 11 are arranged along the circumference of the same circle formed around the object S in the Y-axis direction shown in the Fig. 1. The image pickup devices 31A, 31B, and 31C respectively include cameras 41A, 41B, and 41C, optical filters 42A, 42B, and 42C provided at positions in an image pickup direction, and light attenuation filters 43A, 43B, and 43C provided at positions in the image pickup direction. It should be noted that the image pickup direction is, for example, a direction from the image pickup devices 31 to the subject S.

[0046] The optical filters 42A, 42B, and 42C each allow light of different wavelengths to pass through them. For example, the optical filter 42A allows light with a wavelength corresponding to the color red to pass through it, the optical filter 42B allows light with a wavelength corresponding to the color green to pass through it, and the optical filter 42C allows light with a wavelength corresponding to the color blue to pass through it. It should be noted that the optical filters 42A, 42B, and 42C do not necessarily have properties that allow visible light to pass through them and may have properties that allow infrared or ultraviolet light to pass through them.

[0047] By providing such optical filters 42A, 42B, and 42C, and also by providing image pickup devices 31A, 31B, and 31C that capture images of the subject S in parallel, the information processing device 10 can capture various types of images that have been captured simultaneously. In other words, an image capture period during which images are captured can be shortened. Therefore, even if the light emission intensity of the subject S changes over time, it is possible to capture appropriate captured images without being significantly affected by changes in the light emission intensity.

[0048] The three light attenuation filters 43A, 43B, and 43C correspond to the optical filters 42A, 42B, and 42C, respectively, and adjust the amount of light so that light with an appropriate intensity reaches the corresponding optical filters 42A, 42B, and 42C. As described above, due to the structure in which the light attenuation filters 43A, 43B, and 43C, which are different from each other, are respectively provided in the image pickup devices 31, even if the light transmission rates of the optical filters 42A, 42B, and 42C are different from each other, each image pickup device 31 can capture an image with an appropriate light intensity.

[0049] The Fig. 4 shows changes in the positions of the image pickup devices according to the embodiment of the present invention.

[0050] It is based on the Fig. 1 and Fig. 4. As a result of the first motor 23, which is located in the Fig. 1, causes rotation in the manner described above, the detector unit 11 rotates around the object S in the direction indicated by the arrow E1. Furthermore, as a result of the second motor 24 causing rotation, the detector unit 11 rotates around the object S in the direction indicated by the arrow E2. In other words, as shown in the Fig. As shown in Fig. 4, the image pickup devices 31A, 31B and 31C in the detector unit 11 move along a spherical plane Sp centered around the object S.

[0051] Specifically, the moving angle of each image pickup device 31 in the direction indicated by the arrow E1 is referred to as an angle φ, the moving angle of each image pickup device 31 in the direction indicated by the arrow E2 is referred to as an angle θ, and it is provided that the position of the image pickup device 31B shown in the Fig. 4 is a position defined by "the angle φ = 0°" and "the angle θ = 0°" (hereinafter also referred to as the "initial position"). In this case, the image pickup devices 31A, 31B, and 31C move along the spherical plane Sp, and accordingly, the angle φ and the angle θ of each image pickup device change.

[0052] Here, the information processing device 10 transmits drive instructions to the movable mechanism 12 so that the first motor 23 and the second motor 24 rotate in parallel. Therefore, it is not necessary to stop the image pickup devices 31 in either the direction indicated by the arrow E1 or the direction indicated by the arrow E2 during the image pickup period. Consequently, the image pickup devices 31 can be prevented from wobbling as a result of the stopping. Furthermore, since it is not necessary to stop the image pickup devices 31, the image pickup period can be short.

[0053] The Fig. 5 shows trajectories of the image pickup devices according to the embodiment of the present invention. Fig. 5, the vertical axis indicates the movement angle θ of each image pickup device 31 and the horizontal axis indicates the movement angle φ of each image pickup device 31.

[0054] As it is in the Fig. 5, when the image pickup devices 31A, 31B and 31C move such that the angle φ changes within a range defined by 0° ≤ φ < 360° and the angle θ changes within a range defined by -90° ≤ θ < +90°, a trajectory La of the image pickup device 31A, a trajectory Lb of the image pickup device 31B and a trajectory Lc of the image pickup device 31C are as shown in the Fig. 5. The image pickup devices 31A, 31B, and 31C, which are arranged at physically different angles relative to the object S, move while maintaining the positional relationship between them in the detector unit 11. Therefore, the trajectories La, Lb, and Lc do not overlap with each other.

[0055] It should be noted that the trajectories La, Lb and Lc are not limited to those shown in the Fig. 5. Furthermore, the image pickup devices 31A, 31B and 31C are not necessarily formed so that they extend along the spherical plane Sp shown in the Fig. 4. That is, a plane including the trajectories of the image pickup devices 31 may have a shape other than a spherical shape.

[0056] Furthermore, the information processing device 10 may transmit drive instructions to the movable mechanism 12 so that the first motor 23 and the second motor 24 sequentially cause rotation.

[0057] Furthermore, the image pickup devices 31A, 31B and 31C are not necessarily arranged along the circumference of the same circle centered around the object S in the Y-axis direction shown in the Fig. 1 is shown.

[0058] Furthermore, the detector unit 11 may be formed without the light attenuation filters 43A, 43B and 43C.

[0059] Analysis processing performed by the information processing device Calculation of correction coefficients

[0060] It is again pointed out that Fig. 1 to 4. The information processing device 10 receives the measurement result of the spectrum of light from the spectrometer 13 and calculates a correction coefficient for each of the image pickup devices 31 based on the measurement result thus received.

[0061] In particular, the carrier platform 14, which is located in the Fig. 1, in a direction indicated by arrow E3. For example, the user rotates the support platform 14 to change the orientation of the object S such that the spectrometer 13 is positioned in front of the object S. In other words, the user changes the orientation of the object S such that the positional relationship between the spectrometer 13 and the object S is identical to the positional relationship between the image pickup device 31 at the above-described initial position and the object S. Thereafter, the information processing device 10 transmits a measurement instruction to the spectrometer 13 according to a user operation.

[0062] After receiving a measurement instruction from the information processing device 10, the spectrometer 13 measures the spectrum of light from the object S according to the measurement instruction and transmits the measurement result to the information processing device 10. The information processing device 10 receives the measurement result from the spectrometer 13 and acquires, for example, spectral values ​​Xλ, Yλ and Zλ of light from the object S based on the measurement result thus received.

[0063] Next, the user rotates the support platform 14 to change the orientation of the object S such that the detector unit 11 is positioned in front of the object S. Thereafter, the information processing device 10 transmits, for example, drive instructions to the movable mechanism 12 according to a user operation so that the image pickup devices 31A, 31B, and 31C move sequentially to the initial position, and thus the information processing device 10 changes the position of the detector unit 11.

[0064] Thereafter, the information processing apparatus 10 acquires an image captured by the image capturing device 31A at the initial position, an image captured by the image capturing device 31B at the initial position, and an image captured by the image capturing device 31C at the initial position.

[0065] The information processing device 10 also detects the intensity of light of each color based on the three captured images thus acquired. Specifically, the information processing device 10 calculates the intensity of light having a wavelength corresponding to the color red based on the image captured by the image pickup device 31A from the initial position. The information processing device 10 also calculates the intensity of light having a wavelength corresponding to the color green based on the image captured by the image pickup device 31B from the initial position. The information processing device 10 also calculates the intensity of light having a wavelength corresponding to the color blue based on the image captured by the image pickup device 31C from the initial position.

[0066] The Fig. 6 shows the processing performed by the information processing apparatus according to the embodiment of the present invention for calculating the light intensity.

[0067] It is based on the Fig. 6. If the intensities of light rays reaching an analysis point Ap from several points on the surface of the object S are respectively referred to as intensities I0, I1, I2, etc., the intensity of light reaching the analysis point Ap is the sum of the intensities I0, I1, I2, etc.

[0068] Therefore, the information processing device 10 detects the intensity of light corresponding to the color red by summing the pixel values ​​of a plurality of pixels included in the image captured by the image pickup device 31A. The information processing device 10 also detects the intensity of light corresponding to the color green by summing the pixel values ​​of a plurality of pixels included in the image captured by the image pickup device 31B. The information processing device 10 also detects the intensity of light corresponding to the color blue by summing the pixel values ​​of a plurality of pixels included in the image captured by the image pickup device 31C.

[0069] It should be noted that the information processing device 10 may be configured to detect the intensity of light having one color based on a plurality of images each captured by the plurality of image pickup devices 31. For example, the information processing device 10 may be configured to detect the intensity of light corresponding to the color red based on an image captured by the image pickup device 31A from the initial position and an image captured by the image pickup device 31C from the initial position.

[0070] Thereafter, the information processing device 10 calculates correction coefficients used for respectively adjusting the intensities of light having the above-described colors detected from the captured images having the spectral values ​​Xλ, Yλ and Zλ corresponding thereto on the basis of the measurement result from the spectrometer 13. Creating a virtual image

[0071] Based on the images captured by the image pickup devices 31, the information processing device 10 performs computation processing to generate one or more images (hereinafter referred to as the “virtual images”) of the object S virtually captured from one or more analysis points Ap each located at a position different from a position on the spherical plane Sp including the trajectories of the image pickup devices 31.

[0072] The Fig. 7A and Fig. 7B each shows an example of a virtual image generated by the information processing apparatus according to the embodiment of the present invention.

[0073] It is based on the Fig. 7A and Fig. 7B. It is assumed that a frontal image of the object S, ie, an image of the object S taken from the initial position, which is shown in the Fig. 7A. If this is the case, the information processing device 10 performs a calculation process to generate a virtual image of the object S that has been virtually captured in an oblique direction relative to the object S, as shown, for example, in FIG. Fig. 7B, that is, virtually recorded from an analysis point Ap located at a position different from the initial position.

[0074] The Fig. Fig. 8 shows a method for generating a virtual image used by the information processing apparatus according to the embodiment of the present invention. Fig. Figure 9 shows a method for generating a virtual image used by the information processing apparatus according to the embodiment of the present invention. To simplify the description of the method for generating a virtual image, an image pickup device 31 will be described below.

[0075] As it is in the Fig. 8, it is provided that the analysis point Ap is located on the Y-axis. If this is the case, the information processing device 10 performs, as processing performed to generate a virtual image captured from the analysis point Ap, an analysis of how the object S is projected onto a plane (hereinafter referred to as the "virtual plane") Vp at the center of which the object S is located and which is orthogonal to a vector extending from the analysis point Ap to the center of the object S, and thus acquires a virtual image.

[0076] Furthermore, it analyses how it is in the Fig. As shown in Fig. 9, in a case where the analysis point Ap is not located on the Y-axis, the information processing apparatus 10 accordingly projects the object S onto the virtual plane Vp corresponding to the analysis point Ap and thus acquires a virtual image.

[0077] Specifically, the information processing device 10 performs processing for analyzing light from the object S with respect to a plurality of points included in the virtual plane Vp. The following describes the light analysis processing with respect to a point Px on the virtual plane Vp shown in the Fig. 9 is shown.

[0078] The Fig. Figure 10 shows a light analysis processing with respect to the point Px shown in the Fig. 9 is shown. The Fig. Figure 10 shows the respective positions of the object S, the spherical plane Sp centered around the object S and in the Fig. 4 and the analysis point Ap.

[0079] It is based on the Fig. 10. The information processing device 10 selects a captured image to be used for generating a virtual image from a plurality of images captured by the image pickup device 31 based on the position of the point Px on the virtual plane Vp, the position of the analysis point Ap, and the spherical plane Sp.

[0080] Specifically, the information processing device 10 sets a point D which is an intersection point of a straight line St and the spherical plane Sp, the straight line St passing through the point Px on the virtual plane Vp and the analysis point Ap. Thereafter, the information processing device 10 selects an image captured by the image pickup device 31 when the image pickup device 31 was located at the point D from a plurality of captured images captured by the

[0081] Image recording device 31.

[0082] Thereafter, the information processing device 10 calculates pixel values ​​of the virtual image on the basis of the pixel values ​​corresponding thereto of the thus selected captured image and thus generates the virtual image.

[0083] Specifically, the information processing device 10 sets the pixel value of the pixel corresponding to the point Px on the virtual plane Vp from among the pixels included in the thus selected captured image.

[0084] The information processing device 10 determines the pixel values ​​of all pixels included in the virtual image and thus generates the virtual image. The information processing device 10 then performs output processing, which is processing performed, for example, for displaying the generated virtual image, which is the result of the analysis, on a monitor or the like, or for transmitting the generated virtual image to another device.

[0085] Here overlap, as in the Fig. 5, the respective trajectories La, Lb, and Lc of the image pickup devices 31A, 31B, and 31C do not match each other, and therefore, the image pickup devices 31A, 31B, and 31C cannot acquire an image captured from the same position. However, the information processing device 10 performs calculations using captured images to generate a virtual image for each of the image pickup devices 31A, 31B, and 31C, and thus, the information processing device 10 can generate various types of images virtually captured from the same analysis point Ap.

[0086] Furthermore, as described above, light rays with wavelengths corresponding to the colors red, green and blue, respectively, reach the cameras 41A, 41B and 41C, which are arranged in the Fig. 3. Therefore, the information processing apparatus 10 can generate a virtual color image by generating a virtual image acquired from the same analysis point Ap for each image pickup device 31 and using the thus generated virtual images.

[0087] It should be noted that the method for generating a virtual image employed by the information processing apparatus 10 is not limited to the method described above, which is an example. Compensation processing

[0088] There are cases where an image pickup device 31 does not pick up an image when it is located at the point D which is an intersection point of the straight line St and the spherical plane Sp shown in the Fig. 10, where the straight line St passes through the point Px in the virtual plane Vp and the analysis point Ap. In such cases, the information processing device 10 can compensate the image based on a plurality of images captured by the image pickup devices 31.

[0089] The Fig. 11 shows compensation processing performed by the information processing apparatus according to the embodiment of the present invention.

[0090] As it is in the Fig. 11, the information processing device 10 first selects a plurality of points included in a trajectory L and located near the point D. Thereafter, the information processing device 10 selects a plurality of images each captured from the plurality of thus-selected points from a plurality of images captured by the image pickup device 31. Thereafter, using the plurality of thus-selected captured images, the information processing device 10 generates an image that could have been captured by the image pickup device 31 when it is assumed that the image pickup device 31 was located at the point D.

[0091] For example, it is assumed that the information processing device 10 selects four points P1, P2, P3, and P4. If this is the case, the information processing device 10 generates the above-mentioned one image using four images each taken from the four points P1, P2, P3, and P4 thus selected.

[0092] Processing to calculate light intensity

[0093] The information processing device 10 may be configured to output the light intensity detected based on the virtual image as a result of the analysis, instead of performing processing to output the generated virtual image as a result of the analysis.

[0094] The information processing device 10 calculates the light intensity by summing the pixel values ​​of the plurality of pixels included in the captured image and multiplying the thus calculated light intensity by a correction coefficient. Thus, the information processing device 10 can calculate the light intensity at the analysis point Ap. For example, the information processing device 10 multiplies the sum of the pixel values ​​acquired from an image captured by the image pickup device 31A by a correction coefficient corresponding to the color red. Thus, the information processing device 10 can detect a more accurate light intensity.

[0095] Further, the information processing device 10 generates a virtual image for each of a plurality of analysis points Ap and calculates the light intensity for each of the thus generated virtual images. Consequently, the information processing device 10 can detect the distribution of light intensities on a plane located at any position at a distance from the object S.

[0096] The Fig. 12 shows an example of the distribution of intensities of light that can be detected by analysis processing performed by the information processing apparatus according to the embodiment of the present invention.

[0097] It is based on the Fig. 12. The information processing device 10 calculates the light intensity for each of a plurality of analysis points Ap included in a given plane based on a plurality of images acquired, for example, by the image pickup device 31A. Consequently, the information processing device 10 can acquire an image Vd1 showing the distribution of light intensities on the plane.

[0098] With such an image Vd1, it is easy to visually grasp, for example, the fact that the light intensity is high in an area R1a located near the center of the plane and that the light intensity is low in an edge area R1b.

[0099] The Fig. 13 shows an example of the distribution of intensities of light that can be detected by analysis processing performed by the information processing apparatus according to the embodiment of the present invention.

[0100] It is based on the Fig. 13. The information processing device 10 calculates the light intensity for each of a plurality of analysis points Ap included in a given plane based on a plurality of images acquired by the image pickup device 31A, a plurality of images acquired by the image pickup device 31B, and a plurality of images acquired by the image pickup device 31C, and can thus acquire a color image Vd2 showing the distribution of intensities of light on the plane.

[0101] With such a color image Vd2, it is easy to visually grasp, for example, the fact that the intensity of light with a wavelength corresponding to the color green is high in a region R2a located near the center of the plane, and the intensity of light with a wavelength corresponding to the color yellow is high in a region R2b located slightly above the region R2a, and the intensity of light with a wavelength corresponding to the color red is high in a region R2c located slightly above the region R2b.

[0102] It should be noted that the analysis points AP are not limited to points located at positions different from positions on the plane including the trajectories of the image pickup devices 31, and may be any points located on the spherical plane Sp. Specifically, the information processing device 10 may be configured not to determine whether an analysis point Ap is located on the spherical plane Sp of the image pickup devices 31 or not, and to perform the same analysis processing regardless of whether the analysis point Ap is located on the spherical plane Sp or at a position different from a position on the spherical plane Sp. With such a configuration, the analysis processing can be simplified. Operational process

[0103] The information processing device 10 includes a computer and a computing processing unit, such as a CPU, in the computer. It reads a program including part or all of the following steps of a flowchart from a memory (not shown), and executes the program. This program may be installed externally. Furthermore, this program is distributed in a state in which it is stored on a recording medium.

[0104] The Fig. 14 is a flowchart showing a flow of operations performed by the information processing apparatus according to the embodiment of the present invention.

[0105] As it is in the Fig. As shown in Figure 14, the information processing device 10 first transmits a measurement instruction to the spectrometer 13. As a result, the spectrometer 13 measures a spectrum. Thereafter, the information processing device 10 acquires the measurement result transmitted from the spectrometer 13 and stores the thus acquired measurement result (step S11).

[0106] Next, the information processing apparatus 10 changes the position of the detector unit 11 and acquires a plurality of images captured by the image pickup device 31A, a plurality of images captured by the image pickup device 31B, and a plurality of images captured by the image pickup device 31C, and stores the thus acquired plurality of captured images (step S12).

[0107] Next, the information processing apparatus 10 acquires, for example, from the thus acquired plurality of captured images, an image captured by the image capturing device 31A from the initial position, an image captured by the image capturing device 31B from the initial position, and an image captured by the image capturing device 31C from the initial position (step S13).

[0108] Next, the information processing device 10 calculates three correction coefficients corresponding to the colors red, green, and blue, respectively, based on the thus acquired captured image and the measurement result of the spectrum (step S14).

[0109] It should be noted that the information processing device 10 may acquire the measurement result of the spectrum (step S11) at a time between the acquisition of the captured images (step S12) and the acquisition of the images acquired from the initial position (step S13), or between the acquisition of the images acquired from the initial position (step S13) and the calculation of the correction coefficients (step S14).

[0110] Next, the information processing device 10 sets an analysis point Ap according to a user operation. For example, the user instructs the information processing device 10 to output a color image showing the distribution of light intensities on a given plane as the result of the analysis performed by the information processing device 10. If this is the case, the information processing device 10 sets one of a plurality of points included in the plane specified by the user as the analysis point Ap (step S15).

[0111] Next, the information processing apparatus 10 sets a point Px on the virtual plane Vp corresponding to the analysis point Ap (step S16).

[0112] Next, the information processing apparatus 10 sets, for example, the point D which is an intersection point of the straight line St and the spherical plane Sp centered on the object S, the straight line St passing through the point Px and the analysis point Ap thus set (step S17).

[0113] Next, the information processing device 10 selects, for example, an image captured by the image pickup device 31A when the image pickup device 31A was located at point D from the plurality of captured images stored by the information processing device 10. It should be noted that when the information processing device 10 has not acquired an image captured by the image pickup device 31A from point D, the information processing device 10 performs the above-described image compensation processing to generate an image that could have been captured by the image pickup device 31A when the image pickup device 31A was assumed to be located at point D (step S18).

[0114] Next, the information processing apparatus 10 sets the pixel value of the pixel corresponding to the point Px on the virtual plane Vp from among the pixels included in the thus selected or generated captured image (step S19).

[0115] Next, the information processing device 10 checks whether the information processing device 10 has generated a virtual image, that is, whether the information processing device 10 has set the pixel values ​​of all pixels included in the virtual image (step S20). If there is a pixel whose pixel value has not been set ("NO" in step S20), the information processing device 10 sets a new point Px corresponding to the pixel whose pixel value has not been set (step S16) and executes step S17 and subsequent processing.

[0116] On the other hand, when the information processing device 10 has generated a virtual image, that is, when the information processing device 10 has set the pixel values ​​of all pixels included in the virtual image ("YES" in step S20), the information processing device 10 determines whether or not the information processing device 10 has generated virtual images corresponding to the analysis point Ap for all of the image pickup devices 31A, 31B, and 31C (step S21).

[0117] When the information processing apparatus 10 has not generated a virtual image for at least one of the image pickup devices 31A, 31B, and 31C ("NO" in step S21), the information processing apparatus 10 performs virtual image generation processing, that is, the processing in steps S16 to S20, with respect to the image pickup device 31 for which a virtual image has not been generated.

[0118] On the other hand, if the information processing device 10 has generated virtual images for all of the image pickup devices 31A, 31B, and 31C ("YES" in step S21), the information processing device 10 calculates, for each of the generated virtual images, the sum of the pixel value of the plurality of pixels in the virtual image and calculates a value by multiplying the sum by the correction coefficient as the light intensity. Then, using, for example, the plurality of intensities calculated for the plurality of virtual images, the information processing device 10 calculates the light intensity at the analysis point Ap for each wavelength (step S22).

[0119] Next, the information processing device 10 checks whether the information processing device 10 has calculated the light intensity for all points included in the plane specified by the user (step S23). If there is a point for which the light intensity has not been calculated ("NO" in step S23), the information processing device 10 sets a new analysis point AP (step S15) and performs step S16 and subsequent processing.

[0120] On the other hand, if the information processing device 10 has calculated the light intensity for all points included in the plane specified by the user ("YES" in step S23), the information processing device 10 generates, for example, a color image showing the distribution of light intensities based on the light intensity calculated for each point. Thereafter, the information processing device 10 performs processing to output the thus-generated image as the result of the analysis (step S24).

[0121] It should be noted that the user can set any type of data on the information processing device 10 as data to be output from the information processing device 10 as a result of the analysis, for example, according to the type of the object S.

[0122] For example, it is provided that the user instructs the information processing device 10 to output a virtual color image acquired from the analysis point Ap. If this is the case, the information processing device 10 does not perform the processing in step S22 or S23, generates a virtual color image using three virtual images corresponding to the image pickup devices 31A, 31B, and 31C, respectively, and outputs the virtual color image as the result of the analysis.

[0123] Furthermore, it is provided that the user instructs the information processing device 10 to output, for example, a virtual image captured by the analysis point Ap and corresponding to the image pickup device 31A. If this is the case, the information processing device 10 does not perform the processing in steps S21 to S23 and outputs a virtual image corresponding to the image pickup device 31A as the result of the analysis.

[0124] Further, it is contemplated that the user instructs the information processing device 10 to output an image showing the distribution of light intensities with a wavelength corresponding to the color red on a given plane. If this is the case, the information processing device 10 does not perform the processing in step S21 or S23 and generates an image showing the distribution of light intensities based on the light intensity at each of the plurality of analysis points Ap that can be captured from the virtual image corresponding to the image pickup device 31A. Thereafter, the information processing device 10 outputs the thus generated image as the result of the analysis.

[0125] It should be noted that the spectrometer 13 may be located within the spherical plane Sp, for example, to improve sensitivity. That is, the distance between the spectrometer 13 and the object S may be different from the distance between the image pickup devices 31 and the object S.

[0126] If this is the case, when acquiring images taken from the initial position (step S13), the information processing device 10 generates a virtual image acquired from the analysis point Ap, assuming that the spectrometer 13 is located at the analysis point Ap, based on the plurality of acquired images.

[0127] That is, the information processing device 10 sets the position of the spectrometer 13 as the analysis point Ap and sets the point Px on the virtual plane Vp corresponding to the analysis point Ap. Thereafter, the information processing device 10 selects, from the images captured by the image pickup devices 31, an image captured from the point D, which is an intersection point of the straight line St and the spherical plane Sp, the straight line St passing through the point Px and the analysis point Ap.

[0128] Thereafter, the information processing device 10 determines the pixel value of the pixel corresponding to the point Px on the virtual plane Vp among the pixels included in the thus acquired image. The information processing device 10 determines the pixel values ​​of all pixels included in the virtual image, and thus, the information processing device 10 can generate the virtual image corresponding to the analysis point Ap as an image acquired from the initial position.

[0129] The information processing device 10 is not necessarily configured to calculate a correction coefficient, and it may be configured not to calculate a correction coefficient when the properties of the object S are known, such as when the relative intensity of light at each wavelength is known. That is, the information processing device 10 does not need to perform the acquisition of the result of the spectrum measurement (step S11), the acquisition of the image taken from the initial position (step S13), or the calculation of the correction coefficient (step S14). Furthermore, in this case, the optical property measurement system 200 shown in the Fig. 1 does not include the spectrometer 13.

[0130] There is a need for a technology that makes it possible to acquire more preferable measurement results with a structure for measuring optical properties of an object, such as the light distribution characteristic measuring device disclosed in Patent Document 1, using captured images of the object.

[0131] Taking this need into account, with the optical characteristic measuring method according to the embodiment of the present invention, the information processing apparatus 10 first acquires one or more captured images including the object S using an image pickup device 31 that is located at a predetermined distance from the object S and configured to be displaceable relative to the object S while maintaining the predetermined distance.Next, the information processing device 10 generates, on the basis of the one or more images thus acquired, one or more virtual images including the object S and acquired from one or more analysis points Ap each located at a position different from a position on the spherical plane Sp including the trajectory of the image pickup device 31.

[0132] The inventors of the present invention considered measuring light reaching the analysis points Ap in view of which captured images can be acquired when images of the object S are captured from the analysis points Ap, rather than simply measuring the intensity of light from the object S at the analysis points Ap. As described above, with the method of generating a virtual image of the analysis points AP using an image captured from a point located at a position different from that of the analysis points Ap, it is possible to reliably acquire a larger amount of information at various analysis points Ap, compared with a method of simply measuring the intensity of light from the object S at one analysis point Ap.Therefore, with a setup for measuring optical properties of the object S using one or more captured images of the object S, more preferable measurement results can be acquired.

[0133] Furthermore, with the method described above, it is unnecessary to dispose the image pickup device 31 at an actual analysis point Ap. Therefore, even if the analysis point Ap is located away from the object S, it is possible to reduce the distance from the object S to the image pickup device, and the overall system can be downsized.

[0134] Further, in the optical characteristic measurement method according to the embodiment of the present invention, when generating a virtual image, the information processing device 10 generates a plurality of virtual images each acquired from a plurality of analysis points Ap. Further, the information processing device 10 calculates the sum of pixel values ​​of each of the plurality of thus generated virtual images.

[0135] Using such a method, the light intensity can be calculated for each analysis point Ap. Therefore, the distribution of light intensities at any level can be captured with high accuracy.

[0136] Further, in the optical characteristic measuring method according to the embodiment of the present invention, when generating a virtual image, the information processing device 10 selects one captured image from a plurality of images captured from the trajectory L based on a position on the virtual plane Vp corresponding to the virtual image, the position of the analysis point Ap, and the spherical plane Sp, and generates the virtual image based on the thus selected captured image.

[0137] With such a method, a suitable captured image can be selected for each position on the virtual plane Vp according to the position on the virtual plane Vp, the position of the analysis point Ap, and the trajectory L. Therefore, a virtual image with high accuracy can be generated.

[0138] Further, in the optical characteristic measuring method according to the embodiment of the present invention, when generating a virtual image, the information processing device 10 selects a plurality of captured images from a plurality of images captured from the trajectory L, and generates a virtual image based on an image generated from the plurality of thus selected captured images.

[0139] With such a method, in a case where there is no captured image corresponding to a position on the virtual plane Vp and the position of the analysis point Ap captured from the trajectory L, it is possible to select a plurality of appropriate images and generate a virtual image with high accuracy.

[0140] Furthermore, in the optical characteristic measurement method according to the embodiment of the present invention, when acquiring one or more captured images, the information processing device 10 uses a plurality of image pickup devices 31 each capturing images at different wavelengths, and when generating a virtual image, the information processing device 10 generates a virtual image for each of the image pickup devices 31.

[0141] With such a method, for example, a plurality of captured images with a plurality of wavelengths can be acquired simultaneously. Furthermore, it is possible to capture captured images with different wavelengths in parallel and shorten the image acquisition period. Therefore, even if the intensity of light from the object S changes over time, it is possible to capture a preferred captured image without being significantly affected by such changes.

[0142] Further, in the optical characteristic measuring method according to the embodiment of the present invention, when acquiring one or more captured images, the information processing apparatus 10 uses a plurality of image pickup devices 31 arranged along the circumference of the same circle centered on the object S.

[0143] In this way, by arranging a plurality of image pickup devices 31 such that the distance between each image pickup device 31 and the object S is identical, the calculation processing can be simplified when, for example, an analysis is performed using a plurality of virtual images each generated for the plurality of image pickup devices 31.

[0144] Further, in the optical characteristic measuring method according to the embodiment of the present invention, when acquiring one or more captured images, the information processing apparatus 10 uses a plurality of image pickup devices 31 including light attenuation filters 43A, 43B, and 43C provided at positions in the image pickup direction.

[0145] With such a method, even if the light transmission rates of the plurality of optical filters 42A, 42B, and 42C respectively provided in the plurality of image pickup devices 31 are different from each other, each image pickup device 31 can capture an image having an appropriate light intensity.

[0146] Furthermore, in the optical characteristic measurement system 200 according to the embodiment of the present invention, an image pickup device 31 is located at a predetermined distance from the object S. The movable mechanism 12 is configured to change the position of the image pickup device 31 relative to the object S while maintaining the predetermined distance. Based on an image captured by the image pickup device 31 and including the object S, the information processing device 10 can generate a virtual image including the object S and detected by one or more analysis points Ap, each located at a position different from a position on the spherical plane Sp including the trajectories L of the image pickup devices 31.

[0147] The inventors of the present invention have considered the measurement of light reaching the analysis points Ap in view of which captured images can be acquired when images of the object S are acquired from the analysis points Ap, rather than simply measuring the intensity of light from the object S at the analysis points Ap. As described above, with a structure that uses an image acquired from a point located at a position different from the analysis points Ap and can thereby generate a virtual image acquired from the analysis point, larger amounts of information can be reliably acquired at different analysis points Ap, compared with a structure that simply measures the intensity of light from the object S at one analysis point Ap.Therefore, with a setup for measuring optical properties of the object S using captured images of the object S, more preferable measurement results can be acquired.

[0148] Furthermore, with the above-described structure, it is unnecessary to dispose the image pickup device 31 at an actual analysis point Ap. Therefore, even if the analysis point Ap is located away from the object S, it is possible to reduce the distance from the object S to the image pickup device, and the overall system can be downsized.

[0149] Further, in the optical characteristic measurement system 200 according to the embodiment of the present invention, the information processing device 10 generates a plurality of virtual images each acquired from a plurality of analysis points Ap, and calculates the sum of pixel values ​​of each of the plurality of virtual images thus generated.

[0150] With such a setup, the light intensity can be calculated for each analysis point Ap. Therefore, the distribution of light intensities at any level can be captured with high accuracy.

[0151] Further, in the optical characteristic measurement system 200 according to the embodiment of the present invention, the information processing device 10 selects one captured image from a plurality of images captured from the trajectory L based on a position on the virtual plane Vp corresponding to the virtual image, the position of the analysis point Ap, and the spherical plane Sp, and generates the virtual image based on the thus selected captured image.

[0152] With such a setup, a suitable captured image can be selected for each position on the virtual plane Vp according to the position on the virtual plane Vp, the position of the analysis point Ap, and the trajectory L. Therefore, a virtual image with high accuracy can be generated.

[0153] Further, in the optical characteristic measurement system 200 according to the embodiment of the present invention, the information processing device 10 selects a plurality of captured images from a plurality of images captured by the trajectory L of the image pickup device 31, and generates a virtual image based on an image generated from the plurality of thus selected captured images.

[0154] With such a structure, in a case where there is no captured image corresponding to a position on the virtual plane Vp and the position of the analysis point Ap captured from the trajectory L, a plurality of appropriate images can be selected, and a virtual image can be generated with high accuracy.

[0155] Furthermore, in the optical property measurement system 200 according to the embodiment of the present invention, a plurality of image pickup devices 31 each capture images at different wavelengths. Furthermore, the information processing device 10 generates a virtual image for each of the image pickup devices 31.

[0156] With such a setup, a plurality of captured images can be acquired at a plurality of wavelengths, for example, simultaneously. Furthermore, captured images at different wavelengths can be acquired in parallel, and the image acquisition period can be shortened. Therefore, even if the intensity of light from the object S changes over time, it is possible to capture preferred captured images without being significantly affected by such changes.

[0157] Furthermore, in the optical property measurement system 200 according to the embodiment of the present invention, the image pickup devices 31 are arranged along the circumference of the same circle centered on the object S.

[0158] In this way, with a structure in which a plurality of image pickup devices 31 are arranged so that the distance between each image pickup device 31 and the object S is identical, the calculation processing can be simplified when, for example, an analysis is performed using a plurality of virtual images each generated for the plurality of image pickup devices 31.

[0159] Further, in the optical characteristic measurement system 200 according to the embodiment of the present invention, the image pickup devices 31A, 31B, and 31C each include light attenuation filters 43A, 43B, and 43C provided at positions in the image pickup direction.

[0160] With such a structure, even if the light transmission rates of the plurality of optical filters 42A, 42B and 42C respectively provided in the plurality of image pickup devices 31 are different from each other, each image pickup device 31 can capture an image with an appropriate light intensity. First modification

[0161] The Fig. 15 shows a structure of a first modification of the detector unit according to the embodiment of the present invention.

[0162] In the example described above, the detector unit 11 comprises three image pickup devices 31A, 31B and 31C. In contrast, as shown in the Fig. 15, the first modification of the detector unit 11 includes an image pickup device 51. The image pickup device 51 includes a camera 71, an optical filter unit 72 provided at a position in the image pickup direction, and a light attenuation filter unit 73 provided at a position in the image pickup direction.

[0163] The Fig. 16 shows a structure of the optical filter unit included in the first modification of the detector unit.

[0164] As it is in the Fig. 16, for example, the optical filter unit 72 includes three optical filters 62A, 62B, and 62C and one opening 62D. The optical filters 62A, 62B, and 62C each allow light of different wavelengths to pass through them. For example, the optical filter 62A allows light of a wavelength corresponding to the color red to pass through it, the optical filter 62B allows light of a wavelength corresponding to the color green to pass through it, and the optical filter 62C allows light of a wavelength corresponding to the color blue to pass through it. It should be noted that the optical filters 62A, 62B, and 62C do not necessarily have properties that allow visible light to pass through them and may have properties that allow infrared or ultraviolet light to pass through them.

[0165] The Fig. 17 shows a structure of a light attenuation filter unit incorporated in the first modification of the detector unit.

[0166] As it is in the Fig. For example, as shown in Fig. 17, the light attenuation filter unit 73 includes three light attenuation filters 63A, 63B, and 63C and one aperture 63D. The three light attenuation filters 63A, 63B, and 63C are provided corresponding to the optical filters 62A, 62B, and 62C, respectively, and adjust the amount of light so that light of an appropriate intensity reaches the optical filters 62A, 62B, and 62C corresponding thereto.

[0167] The optical filter unit 72 and the light attenuation filter unit 73 are connected to a motor (not shown). Fig. The information processing device 10 shown in FIG. 1 transmits, for example, a drive instruction to the motor via a LAN according to a user operation. After receiving the drive instruction from the information processing device 10, the motor rotates according to the drive instruction. As a result of the motor rotating, the optical filter unit 72 and the light attenuation filter unit 73 rotate integrally in a direction indicated by arrow E4.

[0168] As a result of rotating the optical filter unit 72, one of the optical filters 62A, 62B and 62C and the opening 62D are positioned in front of a lens 74 of a camera 71.

[0169] Further, the light attenuation filter unit 73 rotates such that the light attenuation filter 63A is positioned in front of the lens 74 when the optical filter 62A is positioned in front of the lens 74.

[0170] Furthermore, the light attenuation filter unit 73 rotates such that the light attenuation filter 63B is positioned in front of the lens 74 when the optical filter 62B is positioned in front of the lens 74. Furthermore, the light attenuation filter unit 73 rotates such that the light attenuation filter 63C is positioned in front of the lens 74 when the optical filter 62C is positioned in front of the lens 74.

[0171] For example, in a state where the optical filter 62A is positioned in front of the lens 74, the information processing apparatus 10 transmits an image pickup instruction to the image pickup device 51 while the first motor 23 and the second motor 24 shown in the Fig. 1. As a result, the information processing device 10 acquires a plurality of captured images that include the object S in the center and correspond to the color red.

[0172] Further, for example, in a state where the optical filter 62B is positioned in front of the lens 74, the information processing device 10 transmits an image pickup instruction to the image pickup device 51 while the first motor 23 and the second motor 24 rotate. As a result, the information processing device 10 acquires a plurality of captured images that include the object S at the center and correspond to the color green.

[0173] Further, for example, in a state where the optical filter 62C is positioned in front of the lens 74, the information processing device 10 transmits an image pickup instruction to the image pickup device 51 while the first motor 23 and the second motor 24 rotate. As a result, the information processing device 10 acquires a plurality of captured images that include the object S at the center and correspond to the color blue.

[0174] With such a structure in which the optical filter unit 72 and the light attenuation filter unit 73 are provided, various types of captured images can be acquired without providing a plurality of image pickup devices 51, and therefore, the cost can be reduced.

[0175] The further structure and the further processes are identical to those of the system for measuring optical properties 200 described above, so that a detailed description is not repeated here. Second modification

[0176] The above example shows a case where images captured by the image pickup devices 31 show the subject S at the centers of the captured images. However, the position of the subject S in a captured image may be shifted from the center of the captured image. Taking such a case into account, a second modification of the information processing device 10 may correct position information indicating the position of each pixel of a captured image.

[0177] For example, the information processing device 10 acquires a correction value for correcting position information in advance for each of the image pickup devices 31. Specifically, a correction value indicates a shift between the position of the pixel in which the center of the object S is captured in a captured image and the position of the pixel at the center of the captured image.

[0178] For example, when an image is captured that has been taken by the image pickup device 31A (step S12 shown in the Fig. 14), the information processing device 10 corrects position information such that the position of each pixel of the captured image is shifted by an amount indicated by a correction value corresponding to the image pickup device 31A.

[0179] The same correction is performed on an image captured by the image pickup device 31B and on an image captured by the image pickup device 31C. Thereafter, the information processing device 10 performs a calculation based on the corrected position information in step S13 and the subsequent steps shown in the Fig. 14 are shown.

[0180] Specifically, in contrast to a structure in which position information is not corrected, the second modification of the information processing device 10 sets, in a captured image that has been selected or generated, the pixel value of a pixel that is shifted by an amount indicated by the correction value corresponding to the image capturing device 31 (step S19 shown in FIG. Fig. 14 is shown).

[0181] In this way, in the optical characteristic measuring method according to the embodiment of the present invention, when one or more captured images are acquired, the information processing device 10 corrects position information indicating the positions of the pixels of one or more images acquired by each of the plurality of image acquisition devices 31.

[0182] With such a method, even if the position of the object S is different in each of the images captured by the plurality of image pickup devices 31, it is possible to perform correction such that the position of the object S is identical in each captured image and then generate a virtual image for each wavelength. Therefore, even more preferable measurement results can be acquired.

[0183] Furthermore, in the optical characteristic measurement system 200 according to the embodiment of the present invention, the information processing device 10 can correct position information indicating the position of each pixel of one or more images captured by a plurality of image capturing devices 31.

[0184] With such a configuration, even if the position of the object S is different in each of the images captured by the plurality of image pickup devices 31, it is possible to perform correction such that the position of the object S is identical in each captured image and then generate a virtual image for each wavelength. Therefore, more preferable measurement results can be acquired.

[0185] The further structure and the further processes are identical to those of the system for measuring optical properties 200 described above, so that a detailed description is not repeated here.

Claims

[1] Method for measuring optical properties for measuring optical properties of an object (S), the method for measuring optical properties comprising: a step of capturing one or more captured images comprising the object (S) using an image capturing device (31, 51) located at a predetermined distance from the object (S) and displaced relative to the object (S) on a trajectory (L) while maintaining the predetermined distance; and a step of generating, on the basis of the one or more captured images thus acquired, a virtual image comprising the object (S) and virtually acquired from one or more analysis points (Ap) each located at a position different from a position on a plane comprising the trajectory (L) of the image capturing device (31, 51). [2] Method for measuring optical properties according to claim 1, wherein in the step of generating the virtual image, a plurality of virtual images which have been virtually captured from a plurality of analysis points (Ap) are generated, and the method for measuring optical properties further a step of calculating the sum of pixel values of each of the plurality of virtual images thus generated. [3] The optical characteristic measuring method according to claim 1 or 2, wherein in the step of generating the virtual image, one captured image is selected from a plurality of images captured from the trajectory (L) on the basis of a position on a virtual plane (Vp) corresponding to the virtual image, the position of each of the one or more analysis points (Ap) and the plane, and the virtual image is generated on the basis of the thus selected captured image. [4] The optical characteristic measuring method according to claim 3, wherein in the step of generating the virtual image, a plurality of captured images are selected from a plurality of images captured from the trajectory (L), and the virtual image is generated on the basis of an image generated from the plurality of thus selected captured images. [5] Method for measuring optical properties according to one of claims 1 to 4, wherein in the step of capturing the one or more captured images, a plurality of image capturing devices (31) are used, each capturing images at different wavelengths, and in the step of generating the virtual image, the virtual image is generated for each of the plurality of image pickup devices (31). [6] The optical property measuring method according to claim 5, wherein the step of acquiring the one or more captured images uses the plurality of image pickup devices (31) arranged along the circumference of the same circle centered on the object (S). [7] The optical property measuring method according to claim 5 or 6, wherein in the step of acquiring from the one or more captured images, position information indicating the position of each pixel of the one or more images captured by the plurality of image capturing devices (31) is corrected. [8] The optical characteristic measuring method according to any one of claims 5 to 7, wherein in the step of acquiring the one or more captured images, the plurality of image pickup devices (31) each comprising light attenuation filters (43A, 43B, 43C, 63A, 63B, 63C) provided at positions in an image pickup direction is used. [9] A system for measuring optical properties (200) that measures optical properties of an object (S), the system for measuring optical properties (200) comprising: an information processing device (10); an image recording device (31, 51) located at a predetermined distance from the object (S); and a movable mechanism (12) which changes the position of the image pickup device (31, 51) relative to the object (S) on a trajectory (L) while maintaining the predetermined distance, wherein the information processing device (10) is configured to generate a virtual image comprising the object (S) and which has been virtually captured from one or more analysis points (Ap) located at a position different from a position on a plane comprising the trajectory (L) of the image capturing device (31, 51), on the basis of an image captured by the image capturing device (31, 51) and comprising the object (S). [10] An optical property measuring system according to claim 9, wherein the information processing device (10) is configured to generate a plurality of virtual images each virtually acquired from a plurality of analysis points (Ap), and to calculate the sum of pixel values of each of the plurality of virtual images thus generated. [11] The optical property measuring system according to claim 9 or 10, wherein the information processing device (10) is configured to select one captured image from a plurality of images captured from the trajectory (L) based on a position on a virtual plane (Vp) corresponding to the virtual image, the position of each of the one or more analysis points (Ap) and the plane, and to generate the virtual image based on the thus selected captured image.

Images